The present invention relates to a fixing device for use in an image forming apparatus such as a copier, printer, facsimile device, etc., and particularly to a fixing device for instantaneous heating practicable quick start fixing, and an image forming apparatus therewith.
Conventionally, as a fixing device for use in an image forming apparatus such as a facsimile device, or the like, a heat roller fixing type device is widely adopted from a low speed apparatus to a high speed apparatus, and from a monochromatic apparatus to a full-color apparatus, as the fixing device which has the high technical complication degree and stability.
However, in the conventional heat roller fixing type fixing device, when transfer material or toner is heated, it is necessary that a fixing roller having a large thermal capacity is heated, therefore, the effect of energy conservation is not good, and it is disadvantageous to the phase of the energy conservation, and when printing, it takes a long period of time to warm up the fixing device, therefore the print time (warming up time) takes a long period of time, which is a problem.
In order to solve these problems, a film fixing type fixing device in which a film (heat fixing film) is used, and the thickness of the heat roller is decreased to that of heat fixing film which is the ultimate thickness and the thermal capacity of the heat roller is decreased, and heat conduction efficiency is greatly improved by directly pressure-contacting the temperature controlled-heater (ceramic heater) onto the heat fixing film, and the energy conservation and the quick start which requires almost no warming-up time are intended, and an image forming apparatus therewith are proposed and used recently.
Further, a fixing method in which, as a variation of the heat roller, a ray-transmitting base member is used as a heat-applying roller (a rotary member for applying heat), and a ray from a heat ray filament (a ray generating source) of a halogen lamp (a ray radiation device for radiating ray) provided therein is radiated onto toner and thereby heating and fixing is conducted, and the quick start which requires almost no warming-up time, is intended, is disclosed in Japanese Tokkaisho No. 52-106741, No. 57-82240, No. 57-102736, No. 57-102741, etc. Further, a fixing method, in which a ray absorbing layer is provided on outer peripheral surface of the ray-transmitting base member and thereby, the heat-applying roller (a rotary member for applying heat) is structured, and a ray from a heat ray filament (a ray generating source) of a halogen lamp (a ray radiation device for radiating ray) provided inside the cylindrical ray-transmitting base member is absorbed in the ray absorbing layer provided on the outer peripheral surface of the ray-transmitting base member, and the toner image is fixed by the heat of the ray-absorbing layer, is disclosed in Japanese Tokkaisho No. 59-65867.
However, in the method in which a ray from a heat ray filament (a ray generating source) of a halogen lamp (a ray radiation device for radiating ray) is radiated through the ray-transmitting base member onto toner and thereby heating and fixing is conducted, disclosed in Japanese Tokkaisho No. 52-106741, etc., and in the method in which a ray absorbing layer is provided on outer peripheral surface of the ray-transmitting base member and thereby, the heat-applying roller (a rotary member for applying heat) is structured, a ray from a heat ray filament (a ray generating source) of a halogen lamp (a ray radiation device for radiating ray) is radiated through the ray-transmitting base member onto the ray absorbing layer, and the toner is fixed by the heat of the ray-absorbing layer, the energy conservation and the quick start in which the warming-up time is reduced, are intended, however, the problem occurs that, by the diffusion of the heat to the ray-transmitting base member side in the axial direction (in the radial direction from the center axis of the rotary member for applying heat) of the rotary member for applying heat, instantaneous heating is not conducted. That is, by the flowing-away of the heat from the ray absorbing layer toward the inside, the problem occurs that quick temperature rise-up of the surface temperature of the ray absorbing layer is not carried out.
Further, a problem occurs that, when the transfer material is continuously passing through at the time of fixing, the heat in the lateral direction (in the direction perpendicular to the feeding direction of the transfer material) including the sheet passing section and the sheet non-passing section of the roll-like rotary member for applying heat becomes uneven, and the uniformity of the heat in the lateral direction of the rotary member for applying heat is not obtained. That is, the problem occurs that the uniformity of the heat can not be obtained by the temperature change.
Further, in the above fixing methods, only the ray absorbing layer does not have the heat accumulation action, therefore, the temperature lowering or unevenness of the heat occurs due to the flow-away of the heat from the rotary member for applying heat to the transfer material or to the rotary member for fixing (the fixing roller) provided on the lower side, opposed to the rotary member for applying heat. This occurs from the problem that the temperature of the ray-transmitting base member of the inside of the rotary member for applying heat is low, therefore, the heat is not supplied to the ray absorbing layer, and the temperature stabilization of the ray absorbing layer is not carried out.
Further, in the above fixing methods, a problem that the temperature rising-up speed of the ray absorbing layer of the surface is fast and only the surface is heated, however, the temperature inside the heat applying roller is low, therefore, when print start is conducted soon, the low temperature fixing offset is generated, occurs.
Further, in the above fixing methods, the temperature of the ray absorbing layer of the surface is raised fast, but the temperature inside the rotary member for applying heat hardly rises, and therefore, an appropriate temperature control is not conducted by only detection of the surface temperature of the rotary member for applying heat, and a problem occurs that the low temperature fixing offset is generated.
Further, in the conventional heat roller, the heat roller is heated from the inside of the metallic pipe having good thermal conductivity by a halogen heater, and structured by providing a rubber layer, which is easily deteriorated by heating and has poor thermal conductivity, on the outside (the outer peripheral surface) of the metallic pipe, and it has poor responsibility and the inside temperature is higher than the outside temperature, and has a limitation of the quick start (quick heating). In contrast to this, in the above fixing methods, although the temperature of the ray absorbing layer of the surface can be raised up faster, the inside of the rotary member for applying heat is cool and the temperature is low, therefore, the temperature rise-up technology for such type of a rotary member for applying heat is necessary.
Further, in the above fixing methods, not only the kind of the transfer materials but the inside temperature of the rotary member for applying heat or the temperature of the rotary member for fixing located on the lower side of the rotary member for applying heat influence on the fixing device, and the temperature of the ray absorbing layer of the surface of the rotary member for applying heat rises fast, but the inside temperature hardly rises, therefore, the temperature control for high responsibility is required for the rotary member for applying heat whose temperature lowering is fast.
Further, in an image forming apparatus using the above fixing methods, depending on the temperature of the inside of the rotary member for applying heat, or the temperature of the rotary member for applying heat and the rotary member for fixing provided opposed to the rotary member for applying heat, or the kind of the transfer material or the size thereof, the problem that the continuous printing capacity is different occurs.
An object of the present invention is to prevent the flow-away of the heat from the ray absorbing layer to the inside and to enable the surface temperature of the ray absorbing layer to quickly rise up, and further, to intend to make the heat uniform in the lateral direction including the sheet passing section of the roll-like rotary member for applying heat and the sheet no-passing section and to prevent the diffusion of the heat in the axial direction of the rotary member for applying heat and to prevent the temperature variation inside the rotary member for applying heat, and thereby, to provide a fixing device for instantaneous heating practicable quick start fixing.
Another object of the present invention is to provide the fixing device which can start quickly by preventing the temperature change of the rotary member for applying heat and intending to make the heat uniform and to stabilize the temperature of the ray absorbing layer.
Still another object of the present invention is to provide the fixing device which can quickly start the control to prevent the low temperature fixing offset at the print start.
Further object of the present invention is to provide the fixing device which can quickly start the control to prevent the low temperature fixing offset by forecasting the inside temperature.
Furthermore object of the present invention is provide the fixing device having the temperature-rise technology by which the quick start (quick heating) of the rotary member for applying heat which is a type of rotary member using ray radiation, and whose surface temperature is quickly raised to the appropriate fixing temperature but whose inside temperature is low, can be carried out.
Still furthermore object of the present invention is to provide the fixing device which can control the temperature for the rotary member for applying heat whose temperature is rapidly lowered, at high responsibility, and can quickly start the heating (quick heating).
Still another object of the present invention is to provide an image forming apparatus with the fixing device which can conduct quick start (quick heating), corresponding to the continuous printing capacity which differs depending on the temperature inside the rotary member for applying heat, the temperature of the rotary member for applying heat and the rotary member for fixing provided opposed to the rotary member for applying heat, a kind of transfer materials, and sizes thereof.
The above described objects can be attained by the following fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, having a ray generating source to radiate the ray, inside thereof, a cylindrical ray-transmitting base member having the light transmission property for the ray, and a resilient layer, which are arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray, provided outside the resilient layer, are provided and formed into a roll-shaped rotary member for applying heat; and when the thermal conductivity of the ray-transmitting base member is K1 (J/cmxc2x7sxc2x7K), and the thermal conductivity of the resilient layer is K2 (J/cmxc2x7sxc2x7K), the thermal conductivity K1 of the ray-transmitting base member is K1 greater than K2, as compared to the thermal conductivity K2 of the resilient layer.
Further, the above described objects can be attained by the following fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, having a ray generating source to radiate the ray, inside thereof, a cylindrical ray-transmitting base member having the light transmission property for the ray, and a resilient layer, which are arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray provided outside the resilient layer, are provided and formed into a roll-shaped rotary member for applying heat; and when the thermal conductivity of the resilient layer is K2 (J/cmxc2x7sxc2x7K), and the thermal conductivity of the ray absorbing layer is K3 (J/cmxc2x7sxc2x7K), the thermal conductivity K2 of the resilient layer is K2xe2x89xa6K3, as compared to the thermal conductivity K3 of the ray absorbing layer.
Further, the above described objects can be attained by the following fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, having a ray generating source to radiate the ray, inside thereof, a cylindrical ray-transmitting base member having the light transmission property for the ray, and a resilient layer, which are arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray, provided outside the resilient layer, are provided and formed into a roll-shaped rotary member for applying heat; and when the thermal conductivity of the ray-transmitting base member is K1 (J/cmxc2x7sxc2x7K), the thermal conductivity of the resilient layer is K2 (J/cmxc2x7sxc2x7K), and the thermal conductivity of the ray absorbing layer is K3 (J/cmxc2x7sxc2x7K), then, K2 less than K1, K3.
Further, the above described objects can be attained by the following fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, having a ray generating source to radiate the ray, inside thereof, a cylindrical ray-transmitting base member having the light transmission property for the ray, and a resilient layer, which are arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray, provided outside the resilient layer, are provided and formed into a roll-shaped rotary member for applying heat; and when the thermal capacity of the ray-transmitting base member is Q1 (cal/deg), and the thermal capacity of the resilient layer is Q2 (cal/deg), the thermal capacity Q1 of the ray-transmitting base member is (1/3)xc3x97Q2 less than Q1, as compared to the thermal capacity Q2 of the resilient layer.
Further, the above described objects can be attained by the following fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, having a ray generating source to radiate the ray, inside thereof, a cylindrical ray-transmitting base member having the light transmission property for the ray, and a resilient layer, which are arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray, provided outside the resilient layer, are provided and formed into a roll-shaped rotary member for applying heat; and when the thermal capacity of the resilient layer is Q2 (cal/deg), and the thermal capacity of the ray absorbing layer is Q3 (cal/deg), the thermal capacity Q2 of the resilient layer is Q2 greater than Q3, as compared to the thermal capacity Q3 of the ray absorbing layer.
Further, the above described objects can be attained by the following fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, having a ray generating source to radiate the ray, inside thereof, a cylindrical ray-transmitting base member having the light transmission property for the ray, and a resilient layer, which are arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray, provided outside the resilient layer, are provided and formed into a roll-shaped rotary member for applying heat; and when the thermal capacity of the ray-transmitting base member is Q1 (cal/deg), the thermal capacity of the resilient layer is Q2 (cal/deg), and the thermal capacity of the ray absorbing layer is Q3 (cal/deg), then, Q3 less than Q1+Q2.
The above described objects can be attained by the following fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, a cylindrical ray-transmitting base member having the light transmission property for the ray, which is arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray, provided outside the ray-transmitting base member, are provided and formed into a roll-shaped rotary member for applying heat; and when the ray energy absorption rate of the ray-transmitting base member is a1 (%), and the ray energy absorption rate of the ray absorbing layer is a3 (%), then, a1 greater than a3.
Further, the above described objects can be attained by the following fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, a cylindrical ray-transmitting base member having the light transmission property for the ray, and a cylindrical ray-transmitting resilient layer or ray-transmitting heat insulating layer, which are arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray, provided outside the ray-transmitting resilient layer or ray-transmitting heat insulating layer, are provided and formed into a roll-shaped rotary member for applying heat; and when the ray energy absorption rate of the ray-transmitting base member is b1 (%), the ray energy absorption rate of the ray-transmitting resilient layer or ray-transmitting heat insulating layer is b2 (%), and the ray energy absorption rate of the ray absorbing layer is b3 (%), then, (b1+b2) greater than b3.
Further, the above described objects can be attained by the following fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, a cylindrical ray-transmitting base member having the light transmission property for the ray, which is arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray, provided outside the ray-transmitting base member, are provided and formed into a roll-shaped rotary member for applying heat; and when the minimum temperature inside the layer of the ray-transmitting base member at the time of temperature rise is T1, and the minimum temperature inside the layer of the ray absorbing layer is T3, then, T3 greater than T1.
Further, the above described objects can be attained by the following fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, a cylindrical ray-transmitting base member having the light transmission property for the ray, which is arranged around the ray radiating means for radiating ray, and a cylindrical ray-transmitting resilient layer or ray-transmitting heat insulating layer, having the light transmission property for the ray, and a ray absorbing layer to absorb the ray, provided outside the ray-transmitting resilient layer or ray-transmitting heat insulating layer, are provided and formed into a roll-shaped rotary member for applying heat; and when the minimum temperature inside the layer of the ray-transmitting base member at the time of temperature rise is T11, the minimum temperature inside the layer of the ray-transmitting resilient layer or ray-transmitting heat insulating layer is T21, and the minimum temperature inside the layer of the ray absorbing layer is T31, then, T31 greater than T11, T21.
The above described objects can be attained by the fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, a cylindrical ray-transmitting base member having the light transmission property for the ray, which is arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray, provided outside the ray-transmitting base member, are provided and formed into a roll-shaped rotary member for applying heat; and after the surface temperature of the rotary member for applying heat reaches the fixing proper temperature, the control by which the fixing can be carried out after a predetermined time of heating at the fixing proper temperature, is conducted.
The above described objects can be attained by the fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, a cylindrical ray-transmitting base member having the light transmission property for the ray, which is arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray, provided outside the ray-transmitting base member, are provided and formed into a roll-shaped rotary member for applying heat; and the control in which, after the surface temperature of the rotary member for applying heat exceeds the fixing proper temperature, and is raised up to the excess heating temperature, and is heated at the excess heating temperature, the surface temperature is lowered again to the fixing proper temperature and then, the fixing can be carried out, is conducted.
Further, the above described objects can be attained by the fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, a cylindrical ray-transmitting base member having the light transmission property for the ray, which is arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray, provided outside the ray-transmitting base member, are provided and formed into a roll-shaped rotary member for applying heat; and the internal temperature of the rotary member for applying heat is forecasted by the surface temperature of the rotary member for applying heat and the temperature change, and the temperature control of the rotary member for applying heat is carried out.
Further, the above described objects can be attained by the fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, a cylindrical ray-transmitting base member having the light transmission property for the ray, which is arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray, provided outside the ray-transmitting base member, are provided and formed into a roll-shaped rotary member for applying heat; and the temperature rise-up to the fixing proper temperature of the rotary member for applying heat is conducted by applying the maximum consuming electric power onto the ray radiating means for radiating ray, and after the temperature reaches the fixing proper temperature, the temperature control is conducted.
Further, the above described objects can be attained by the fixing device which is characterized in that: in a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure, a ray radiating means for radiating ray, a cylindrical ray-transmitting base member having the light transmission property for the ray, which is arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray, provided outside the ray-transmitting base member, are provided and formed into a roll-shaped rotary member for applying heat; and temperature detecting means are provided at a front and rear of the nip portion of the rotary member for applying heat, and the setting temperature of the rotary member for applying heat is changed corresponding to the temperature difference between respective temperature detecting means.
Further, the above described objects can be attained by an image forming apparatus which is characterized in that: it has a fixing device by which a toner image on the transfer material is fixed on the transfer material by applying heat and pressure; a ray radiating means for radiating ray, a cylindrical ray-transmitting base member having the light transmission property for the ray, which is arranged around the ray radiating means for radiating ray, and a ray absorbing layer to absorb the ray, provided outside the ray-transmitting base member, are provided, and a roll-shaped rotary member for applying heat is provided; and the rotary member for fixing is provided opposed to the rotary member for applying heat, and thus the fixing device is formed; and the warming-up time of the rotary member for applying heat is changed corresponding to the output form of the image forming apparatus.